Robtex

Up: 31.13.128.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 31.13.136.0/22
Down right: 31.13.140.0/22
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
31.13.136.0	A+PTR	host0-136-dinamic-mon.13-31.reteivo.com
31.13.136.19	PTR	host19-136-dinamic-mon.13-31.reteivo.com
31.13.136.116	A	mon.116.136.reteivo.com
31.13.136.116	A	host116-136-static-mon.13-31.reteivo.com
31.13.136.150	A	mon.150.136.reteivo.com
31.13.136.150	A	host150-136-static-mon.13-31.reteivo.com
31.13.136.215	A	host215-136-static-mon.13-31.reteivo.com
31.13.136.231	A	host231-136-static-mon.13-31.reteivo.com
31.13.136.231	A	mon.231.136.reteivo.com
31.13.136.240	A	host240-136-static-mon.13-31.reteivo.com
31.13.136.250	A	host250-136-static-mon.13-31.reteivo.com
31.13.136.254	A	host254-136-static-mon.13-31.reteivo.com
31.13.137.0	PTR	host0-136-dinamic.13-31.reteivo.com
31.13.137.6	A	mx1.visiaimaging.com
31.13.137.8	PTR	host8-136-dinamic.13-31.reteivo.com
31.13.137.50	PTR	host50-136-dinamic.13-31.reteivo.com
31.13.137.50	A	pratesivini.it
31.13.137.50	A	smtp.pratesivini.it
31.13.137.52	A	fpautopratesi.it
31.13.137.167	A	dns1.winhost.it
31.13.137.168	A	dns2.winhost.it
31.13.137.169	A	mx.winhost.it
31.13.137.212	A	puzzodichianti.com
31.13.137.212	A	videoflashpoint.com
31.13.137.212	A	ilcocco.it
31.13.137.213	A	cpdns01.ivo.cloud
31.13.137.220	A	dtssi.it
31.13.137.251	PTR	mail.nectarine.it
31.13.137.251	A	www.nectarine.it
31.13.137.251	A	nectarine.info
31.13.138.0	A+PTR	host0-138-dinamic.13-31.reteivo.com
31.13.138.7	A	host7-138-dinamic.13-31.reteivo.com
31.13.138.8	A+PTR	host8-138-dinamic.13-31.reteivo.com
31.13.138.21	A	host21-138-dinamic.13-31.reteivo.com
31.13.138.32	A+PTR	host32-138-dinamic.13-31.reteivo.com
31.13.138.48	PTR	host48-138-dinamic.13-31.reteivo.com
31.13.138.74	A+PTR	host74-138-dinamic.13-31.reteivo.com
31.13.138.178	PTR	host178-138-dinamic.13-31.reteivo.com
31.13.138.178	A	intranet.celtex.it
31.13.139.0	PTR	host0-139-dinamic.13-31.reteivo.com
31.13.139.21	A	host21-139-static.13-31.reteivo.com
31.13.139.25	A	host25-139-static.13-31.reteivo.com
31.13.139.138	PTR	host138-139-dinamic.13-31.reteivo.com
31.13.139.138	A	host138-139-static.13-31.reteivo.com
31.13.140.189	A+PTR	host189-140-static.13.31.dtssi.net
31.13.143.1	A	sie1.dtssi.net
31.13.143.2	PTR	lo0.sie2.dtssi.net
31.13.143.2	A	sie2.dtssi.net
31.13.143.6	A	mon.dtssi.net
31.13.143.7	A	vag.dtssi.net
31.13.143.8	PTR	gw-montalcino.pop.dtssi.net
31.13.143.8	A	avr.dtssi.net
31.13.143.9	PTR	lo0.c3350teg.dtssi.net
31.13.143.9	A	teg.dtssi.net
31.13.143.10	PTR	lo0.c3550teg.dtssi.net
31.13.143.10	A	mil3.dtssi.net
31.13.143.12	PTR	lo0.c3550mba.dtssi.net
31.13.143.12	A	ctm.dtssi.net
31.13.143.16	A	mil2.dtssi.net
31.13.143.17	PTR	lo0.1.fir.dtssi.net
31.13.143.17	A	fir1.dtssi.net
31.13.143.18	A	mil1.dtssi.net
31.13.143.21	A	mst.dtssi.net
31.13.143.24	PTR	lo24.sie1.dtssi.net
31.13.143.24	A	sie24.dtssi.net
31.13.143.25	A	cia.dtssi.net
31.13.143.28	PTR	lo0.arg.dtssi.net
31.13.143.28	A	arg.dtssi.net
31.13.143.29	PTR	lo0.c3550gav.dtssi.net
31.13.143.29	A	gav.dtssi.net
31.13.143.32	A+PTR	lo0.smi.dtssi.net
31.13.143.32	A	smi.dtssi.net
31.13.143.33	PTR	lo0.c3350itt.dtssi.net
31.13.143.33	A	itt.dtssi.net
31.13.143.35	PTR	lo0.c3350muz.dtssi.net
31.13.143.35	A	muz.dtssi.net
31.13.143.36	PTR	lo0.mpu.dtssi.net
31.13.143.40	A	acq.dtssi.net
31.13.143.41	A	ant.dtssi.net
31.13.143.88	A	vol.dtssi.net
31.13.143.89	PTR	vlan951.c3550mon.dtssi.net
31.13.143.89	A	alb.dtssi.net
31.13.143.90	PTR	lo0.sec.dtssi.net
31.13.143.90	A	sec.dtssi.net
31.13.143.93	A	cas.dtssi.net
31.13.143.172	A+PTR	cpanel01.ivoweb.it
31.13.143.172	A	www.lalocandadivergelle.it
31.13.143.172	A	www.ilcocco.it
31.13.143.196	A	rad.dtssi.net
31.13.143.197	A	mil4.dtssi.net
31.13.143.198	A	gw-secchieta.pop.dtssi.net